Free Surface Downgoing VSP Multiple Imaging

41st HAGI Annual Convention and Exhibition 2016

Maula, Fahdi^1 ; Dac, Nguyen^1

Schlumberger Data Services, South East Asia, Jalan P Ramlee, Kuala Lumpur, Malaysia^1

关键词: Free surfaces;    Imaging applications;    Multiple imaging;    Non-traditional;    Seismic image;    Shallow hazards;    Vertical seismic profiles;    Well trajectory;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/132/1/012028/pdf
DOI  :  10.1088/1755-1315/132/1/012028

来源: IOP

【 摘 要 】

The common usage of a vertical seismic profile is to capture the reflection wavefield (upgoing wavefield) so that it can be used for further well tie or other interpretations. Borehole Seismic (VSP) receivers capture the reflection from below the well trajectory, traditionally no seismic image information above trajectory. The non-Traditional way of processing the VSP multiple can be used to expand the imaging above the well trajectory. This paper presents the case study of using VSP downgoing multiples for further non-Traditional imaging applications. In general, VSP processing, upgoing and downgoing arrivals are separated during processing. The up-going wavefield is used for subsurface illumination, whereas the downgoing wavefield and multiples are normally excluded from the processing. In a situation where the downgoing wavefield passes the reflectors several times (multiple), the downgoing wavefield carries reflection information. Its benefit is that it can be used for seismic tie up to seabed, and possibility for shallow hazards identifications. One of the concepts of downgoing imaging is widely known as mirror-imaging technique. This paper presents a case study from deep water offshore Vietnam. The case study is presented to demonstrate the robustness of the technique, and the limitations encountered during its processing.